A small aircraft crashed into Beijing’s tallest building, the global flight tracking service provider Flightradar24 confirms, following witness accounts and evacuations in the city’s business district. Photos show what appeared to be a hole in the glass facade on one side of the tower. Images on social media appeared to show debris from a small aircraft near the skyscraper, but their authenticity couldn't be confirmed. The cause of Friday's crash remains unclear, and authorities have not issued a statement. The 108-story tower is one of Beijing's most recognizable landmarks. Recently, Beijing authorities enacted new curbs on its tightly regulated airspace.